Field of Invention
The present invention relates to a light emitting device and a light guide plate of the light emitting device.
Description of Related Art
In recent years, the applications of display devices have become more and more diversified, such as wearable devices, remote controls, electronic tags, advertising boards, etc. Hence, the designs for the shapes of display devices has significantly increased. For example, when a display device is used in a television or computer screen, the shape of the display device is usually rectangular; when a display device is used in a smart watch, the display device may be designed with a round shape, a rhombus shape, or other specific shapes. Accordingly, the shape of a light guide plate disposed in the display device needs to be changed along with the shape of the display device.
Some geometry may affect optical paths in the light guide plate to cause the degradation of desired optical conditions, such as a bright line, a light region, or a dark band. In order to solve the aforesaid problem, when a typical light guide plate is rectangular, a general solution is to form optical dots on a region that has relatively low brightness, such that the brightness of the region is increased to decrease the bright line that is formed by light and dark contrast. However, the aforesaid method of using the optical dots cannot improve an undesired optical condition caused by the shape or edge of the light guide plate. For example, light in a circular light guide plate may be reflected by the edge of the light guide plate, such that bright line may be formed at the semicircle of the light guide plate away from the optical-coupling region of the light guide plate that is adjacent to a light source due to the shape design of the light guide plate. In addition, when a light guide plate has a smooth edge due to its manufacturing process, the smooth edge reflecting light and a corner that light cannot arrive at may form light and dark contrast and a degradation of the desired optical conditions.